<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<title></title>
	<link rel="stylesheet" href="">
</head>
<body>
<div id="watch-example"> 
 <p> 
 Ask a yes/no question: 
 <input v-model="question"> 
 </p> 
 <p>{{ answer }}</p> 
</div>
<script src='http://cdn.jsdelivr.net/vue/1.0.26/vue.js'></script>
<script src='https://cdn.jsdelivr.net/vue.router/0.7.10/vue-router.min.js'></script>
<script src="https://unpkg.com/axios@0.12.0/dist/axios.min.js"></script> 
<script src="https://unpkg.com/lodash@4.13.1/lodash.min.js"></script> 
<script> 
var watchExampleVM = new Vue({ 
 el: '#watch-example', 
 data: { 
 question: '', 
 answer: 'I cannot give you an answer until you ask a question!' 
 }, 
 watch: { 
 // 如果 question 发生改变，这个函数就会运行 
 question: function (newQuestion) { 
  this.answer = 'Waiting for you to stop typing...' 
  this.getAnswer() 
 } 
 }, 
 methods: { 
 // _.debounce 是一个通过 lodash 限制操作频率的函数。 
 // 在这个例子中，我们希望限制访问yesno.wtf/api的频率 
 // ajax请求直到用户输入完毕才会发出 
 // 学习更多关于 _.debounce function (and its cousin 
 // _.throttle), 参考: https://lodash.com/docs#debounce 
 getAnswer: _.debounce( 
  function () { 
  var vm = this 
  if (this.question.indexOf('?') === -1) { 
   vm.answer = 'Questions usually contain a question mark. ;-)' 
   return 
  } 
  vm.answer = 'Thinking...' 
  axios.get('https://yesno.wtf/api') 
   .then(function (response) { 
   vm.answer = _.capitalize(response.data.answer) 
   }) 
   .catch(function (error) { 
   vm.answer = 'Error! Could not reach the API. ' + error 
   }) 
  }, 
  // 这是我们为用户停止输入等待的毫秒数 
  500 
 ) 
 7} 
}) 
</script>	
</body>
</html>